Two pathways or coagulation cascades, known as the intrinsic and extrinsic pathways, lead to the formation of a clot. When a human body is injured, the extrinsic pathway is first triggered to control the in vivo coagulation. In addition to a blood sample, the coagulation reaction needs some additional tissue factors. The inactive factor X is catalyzed into factor Xa. The prothrombin (factor II) can be transformed from the factor Xa to the thrombin (factor IIa) by the effects of factor Va, acidic phospholipids and calcium ions. The thrombin then transforms fibrinogen into fibrin, enhancing the platelet of the endothelial cells gathered at injury. The thrombin can also enhance the role of factor XIII, linking each fibrous protein molecule to a stable fibrin. Therefore, inspecting the prothrombin time would not only determine whether the function of external activation factor of the coagulation system is normal, but also assess and monitor oral anticoagulants treatment, liver function, vitamin K deficiency, coagulation factor deficiency, and disseminated intravascular coagulation (DIC) syndrome.
Some prior art relating electrochemical blood test strips, such as U.S. Pat. No. 7,674,616, the entirety of which is hereby incorporated by reference, disclose a coagulation inspection device with automatically collecting blood samples. The coagulation inspection device determines the coagulation time by measuring capacitance or impedance changes between two electrodes. These technologies may, therefore, improve the simplicity of detection but cannot achieve the high precision and accuracy that the optical detection methods would achieve.
Accordingly, new electrochemical blood test strip and diagnosis system are needed for measuring prothrombin time and HCT with a shortened test time, simplicity and high accuracy.